• The Plant Pathology Journal
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• v.18 no.4
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• pp.216-220
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• 2002

Seed decay of soybean caused by Diaporthe phaseolorum, Colletotrichum truncatum and Cercospora kikuchii is a serious disease when soybean is harvested under warm and wet weather conditions. Benomyl has been used for controlling the disease, however, benomyl application may be limited due to common occurrence of resistance. The efficacy of 21 fungicides against the pathogens was evaluated in vitro. Among the fungicides tested, benomyl, carbendazim, fluazinam, iprodione+propineb, thiophanate-methyl, and triflumizole were found effective and were evaluated for their ability to control the seed pathogens. Fluazinam completely inhibited mycelial growth at a concentration of 100 $\mu\textrm{g}$/$\textrm{m}{\ell}$ for D. phaseolorum; and at a concentration of 500 $\mu\textrm{g}$/$\textrm{m}{\ell}$ for C. truncatum and C. kikuchii. $EC_90$ values of fluazinam were similar to that of benomyl. Because fluazinam, iprodione+propineb, and triflumizole were found effective against the seed pathogens, these were subjected for field-testing. Suppression of pod and seed infection by fluazinam and iprodione+propineb was as high as that of benomyl without any reduction in agronomic characters of soybean. This study shows that fluazinam and iprodione+propineb may be used in combination with benomyl to control seed pathogens, manage resistance, and ensure production of high quality soybean seeds.

• Korean Journal Plant Pathology
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• v.1 no.2
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• pp.128-135
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• 1985

Responses to the 14 fungicides added in PSA of penicillium expansum isolated froms the four major apple growing areas in Korea were examined. Degrees of the fungal tolerance were various with little difference by area and with great difference by kind and concentration of fungicide. Fall isolates of the fungus grew at higher fungicide concentration than did the spring isolates. $ED_{50}$ and MIC to mycelial growth of genomyl, garbenda, polydong, polyoxin and thiophanate methyl were $0.1{\mu}g-41.7{\mu}g/ml\;and\;100{\mu}g-2,250{\mu}g/ml,$, respectively, indicating high fungicide effects on the fungus isolated from decayed apples in storages and infected apples in orchards with low fungal tolerance; of captafol, captan, iprodione and mancozeb were $2.6{\mu}g - 750{\mu}g/ml\;and\;638{\mu}g-40,500{\mu}g/ml$, respectively, indicating medium degree of both fungicidal effects and fungal tolerance; and of chlorothalonil, folpet, oxidong, propineb and triademefon were $27.8{\mu}g-8,354{\mu}g/ml\;and\;2,625{\mu}g-150,357{\mu}g/ml$, respectively, indicating low fungicide effects and high fungal tolerance. Fungicidal inhibitory effects on conidia formation exhibited a similar trend as on mycelial growth whereas those on conidia germination showed an opposite trend to the mycelial growth with the exception of polyoxin and triademefon.

• The Korean Journal of Mycology
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• v.14 no.1
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• pp.71-78
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• 1986

Of the 1,200 single spore isolates of Alternaria mali causing apple leaf spot and fruit decay, the mycelial colonies showed 76, 96 and 15% growth at 100,000 ${\mu}g/ml$ of captafol, chlorothalonil and folpet, respectively, and five and three percent growth at 10,000 ${\mu}g/ml$ of iprodione and polyoxin. These isolates showed cross-tolerance of mycelial growth, spore formation, or spore germination to the above five fungicides plus captan, garbenda, and thiophanate methyl. Captafol, mancozeb, polydong, and propineb did not show any cross-tolerance of spore germination since no spore was germinated at 100 ${\mu}g/ml$ which was much lower than the concentration used by apple growers. Benomyl, fenarimol, oxidong, and triademefon showed medium degree of cross-tolerance of the fungal growth, sporulation, and spore germination.

• The Korean Journal of Pesticide Science
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• v.7 no.4
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• pp.280-287
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• 2003

To assess the risk of pesticides on earthworm, the acute toxicities of 10 pesticides were investigated and their toxicity exposure ratios(TERs) were calculated. As the TERs of paraquat dichloride and pendimethalin were more than 100, their risks were rated negligible. Risk of benfuracarb, cadusafos, chlorpyrifos-methyl, endosulfan, isazofos and parathion which have TERs of $10\sim100$ were rated low. However, risk of imidacloprid and phorate which have TER of less than 10 were estimated highly to need a reproduction study. Earthworms were exposed to twenty two pesticides including dazomet 98% GR having PECs of more than $5mg{\cdot}kg^{-1}$ in artificial soil at standard and double dose for 14 days. All the earthworms exposed to dazomet 98% GR and metam-sodium 25% SL were died to show their high risk, while no serious adverse effects were observed in the soil treated with 15 pesticides, calcite 95% WP, calcium polysulfide 36% CF, chlorothalonil 75% WP, daminozide 85% WP, dichlonil 6.7% GR, etridiazole 25% EC, fosetyl-Al 80% WP, glyphosate 41 % SL, hymexazol 30% SL, iprodione 50% WP, machine oil 95% EC, mancozeb 75% WP, propineb 70% WP, terbuthylazine 80% WP and triazophos 40% EC. In case of thiophanate-methyl 70% WP, copper hydroxide 77% WP, dimethoate 46% EC, tolclofos-methyl 50% WP and propamocarb hydrochloride 67% SL, any effect did not show clearly, suggesting an additional subchronic toxicity study. The risk of thiophanate-methyl 70% WP to earthworm was estimated high, considering its subchronic effect, while effects of copper hydroxide 77% WP, dimethoate 46% EC, tolclofos-methyl 50% WP and propamocarb hydrochloride 67% SL to earthworms were negligible, considering no adverse effects in subchronic tests.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.40-46
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• 2000

To select the effective fungicides for the control of leaf spot disease of jujube tree (Zizyphus jujuba) caused by Phoma sp., inhibitory effects of 26 fungicides for mycelial growth were investigated at $250{\mu}g\;a.i./m{\ell}$. In the test, eight fungicides were selected and minimum inhibitory concentration (MIC) for mycelial growth and an inhibitory effect for spore germination were investigated. Among the fungicides, myclobutanil, hexaconazole, and triflumizole were excluded in control effect tests because of their relatively high MICs. MICs were ranged $10-50{\mu}g\;a.i./m{\ell}$ for benomyl, carbendazim + kasugamycin (CK), and thiophanate-methyl. triflumizole (TT), and $50-250{\mu}g\;a.i./m{\ell}$ for iprodione + propineb (IT) and iminoctadine-triacelate (IT). However, benomyl and IP showed very low inhibitory effect on conidial germination. When the fungicides were sprayed on the seedlings before the leaves were inoculated with conidial suspension of Phoma sp., the protective values of CK and TT were around 70% at 1,000 ppm and around 90% at 2,000 ppm. The protective values were around 70% at 2,000 ppm (benomyl), 4,000 ppm (IP), and 8,000 ppm (IT). When the fungicides were sprayed after inoculation, benomyl showed the highest curative values of over 90% at 1,000 ppm and the values of CK and TT ranged $70{\sim}80%$ at 1,000 ppm. However, IP and IT had little or no effect on therapy of the disease. IT caused necrotic phytotoxicity on the leaves of jujube seedlings. As results, the best fungicides for the protection of jujube trees from leaf spot disease were CK (2,000 ppm) and TT (2,000 ppm) and for the remedy of the tree, benomyl (1,000 ppm) was the best. Therefore, alternate application of benomyl and CK or TT will be effective in the disease control.